This invention relates in general to furniture and more particularly to a swivel unit for furniture.
Some articles of furniture are equipped with swivel assemblies or units to enable the furniture, or at least a component of it, to be turned to various positions without physically lifting the furniture. For example, it is not uncommon to provide a so-called bar chair, particularly one having a back, with a swivel unit immediately below the seat of the chair so that the seat can be turned to afford easy access to it in the confined area around a bar. Similarly, boat seats are ofen equipped with swivels. Many television stands have a base and a swivel platform on which a television receiver rests so that the receiver can be turned to a wide variety of positions with little effort.
Perhaps the greatest use of swivel units for furniture occurs with bar chairs, and the conventional swivel unit for that use consists of nothing more than an upright tube that is anchored firmly on the furniture base and has a horizontal plate at its upper end, another plate located over the horizontal plate and having the seat attached to it, a single row of balls between the two plates, and a rivet joining the two plates together. To retain the balls in place, each of the two plates has an annular groove, and these grooves are located directly opposite to each other and concentric to the rivet. They receive the balls and thereby serve as raceways.
The typical swivel unit is sold to furniture manufacturers as a unit, and not as individual components, since no furniture manufacturer would want to undertake the tedious procedure of installing the bearing balls between the two plates of each unit, nor could this assembly operation be left for the ultimate consumer, even though such furniture is often sold in a knocked-down condition to facilitate storage and minimize transportation expenses. The furniture manufacturer usually applies paint to the swivel unit, and since the unit cannot be dismantled for painting, this paint often enters the space between the two plates and adheres to the raceways or balls, making the upper plate difficult to turn. Furthermore, because of the bearing, the unit should not be immersed in cleaning solvents, and this makes it difficult to prepare the unit for painting. For the same reason, the units cannot be plated, so such units are almost universally painted. Aside from that the two plates are rough steel stampings which have neither the precision nor the hardness normally associated with bearings. This coupled with the tight rivet connection often results in units that do not rotate with the ease that is desired. Finally, since the balls and the raceways are bare metal that is exposed to the atmosphere, they will in time rust, and this, of course, also makes the unit difficult to rotate.